Platelet-rich plasma plus hyaluronic acid injections for knee osteoarthritis

Combined Use of PRP and Hyaluronic Acid for Infiltrative Treatment of Patients With Knee Osteoarthritis - Randomized Controlled Clinical Study

Not applicable Interventional Istituto Ortopedico Rizzoli · NCT06685120

We will try a single injection of platelet-rich plasma plus hyaluronic acid, platelet-rich plasma alone, or hyaluronic acid alone to see which works best for adults (40–75) with unilateral knee osteoarthritis who still have pain after conservative treatment.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment288 (estimated)
Ages40 Years to 75 Years
SexAll
SponsorIstituto Ortopedico Rizzoli Academic / other
Locations2 sites (Bologna and 1 other locations)
Trial IDNCT06685120 on ClinicalTrials.gov

What this trial studies

This is a randomized, double-blind, 1:1:1 trial enrolling 288 adults with unilateral symptomatic knee osteoarthritis (Kellgren-Lawrence grade 1–3) who have failed conservative therapy. All participants will have blood drawn to enable blinded procedures, then be randomized to receive a single intra-articular injection of PRP+HA, PRP alone, or HA alone. Patients, outcome assessors, and data analysts will be blinded to allocation, and PRP will be prepared from autologous whole blood for the PRP arms while the HA arm will undergo sham processing to preserve blinding. Clinical and functional outcomes and safety will be measured over scheduled follow-up visits according to the protocol.

Who should consider this trial

Good fit: Adults aged 40–75 with unilateral symptomatic knee osteoarthritis (Kellgren-Lawrence grade 1–3), VAS pain 3–8, who have persistent symptoms after conservative treatment and meet basic hemoglobin and platelet criteria are ideal candidates.

Not a fit: Patients with advanced osteoarthritis (KL grade 4), inflammatory or rheumatic joint diseases, recent knee surgery or intra-articular injections, malignancy, inability to consent, or inadequate hemoglobin/platelet counts are unlikely to be eligible or to benefit.

Why it matters

Potential benefit: If successful, combining PRP with hyaluronic acid could provide greater pain relief and improved joint function than either treatment alone.

How similar studies have performed: Previous studies of PRP or hyaluronic acid alone have shown mixed but sometimes positive results, and combining them is a relatively new approach with promising but not yet definitive evidence.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Male or female patients, aged 40 to 75 years;
2. Patients with symptomatic knee osteoarthritis (VAS pain score between ≥ 3 and ≤ 8);
3. Unilateral involvement of symptomatology;
4. Radiographic or MRI signs of degenerative pathology of knee cartilage (Kellgren-Lawrence grade 1-3);
5. Failure, defined as the persistence of symptomatology, after at least one course of conservative treatment (pharmacological, physiotherapeutic or infiltrative treatment);
6. Hemoglobin \> 11 g/dl; Platelet count \> 150,000 plt/mm3 (Recently performed CBC examination);
7. Ability and consent of patients to actively participate in clinical follow-up;
8. Signature of informed consent.

Exclusion Criteria:

1. Patients unable to express consent;
2. Patients undergoing intra-articular infiltration of other substance in the previous 6 months;
3. Patients undergoing knee surgery in the previous 12 months;
4. Patients with malignant neoplasms;
5. Patients with rheumatic diseases;
6. Patients with uncontrolled diabetes;
7. Patients with hematological diseases (coagulopathies);
8. Patients on anticoagulant-antiaggregant therapy that cannot be discontinued at the time of blood collection;
9. Patients with uncompensated thyroid metabolic disorders;
10. Patients abusing alcoholic beverages, drugs or medications;
11. Body Mass Index \> 35;
12. Patients who have taken NSAIDs in the 3 days prior to blood draw;
13. Patients with cardiovascular disease for whom blood sampling 30 to 60 ml would be contraindicated;
14. Patients with recently performed CBC examination with Hb\< 11 g/dl and Platelet values \< 150,000 plt/mm3.
15. Pregnant and/or fertile women.

Where this trial is running

Bologna and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Osteo Arthritis KneePRPPlatelet rich plasmaHAHyaluronic acidPRP injectionPRP + HA injectionHA injection
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.